Process and installation for the transverse reinforcement of pipes and other pieces



Dec. 1, 1942. J. BOUCHER 2,303,601

PROCESS AND INSTALLATION FOR THE TRANSVERSE REINFORCEMENT'OF PIPES AND OTHER PIECES Filed June 7, 1939 jacisues 500018 Y //vkE/v 131C Patented Dec. 1, 1942 mouss AND INSTALLATION FOR THE TBANSVERSE REINFORCEMENT OF PIPES AND OTHER PIECES Jacques Boucher,

Societe Ano e des Fonderies de Pont-a-Mousson,

Paris, France, assignor to Hauts-Fourneaux et Pont-a-Mousson, France, a company of France Application June In France 2 Claims.

thermal treatment of steel wire which consists in heating the wire above a point of transformation, and in then suddenly lowering its temperature, for instance by passing it through a bath -of melted metal or alloy (lead or the like), this 1 thermal treatment being intended to change the mechanical or other properties of the wire and particularly to increase its tensile strength.

The present invention has for its object to provide a process for the transverse reinforcement of pipes and other pieces, which comprises submitting the reinforcing wire to a thermal treatment prior to the winding operation by heating it and then cooling it abruptly, so that after this thermal treatment the wire will be at a temperature above the normal temperature whereby the heating necessary for the expansion of the wire is eliminated or at least greatly reduced. A great saving of heat may thus be realised.

Preferably, the initial heating is effected electrically and the abrupt lowering of temperature is effected by passing the wire through a bath of a melted metal or alloy.

The invention has also for its object to provide an installation for carrying said process into effect. According to the invention, it comprises in combination a reel or other device for supplying the wire, a device for heating the wire at a temperature above a point of transformation of the metal or alloy of which is made the wire, a device for lowering abruptly the temperature of the wire and a winding lathe.

The accompanying drawing is a very diagrammatic view of an installation in conformity with the invention.

According to the embodiment illustrated, the installation comprises a reel I from which is unwound the reinforcing wire 2. This wire passes over a brush 3 connected through a rheostat 4 or other regulating device to one terminal of an electric source 5. The wire 2 passes then over rollers 6, I and 8, whereby it is caused to dip into a bath 9 of melted lead or other metal or alloy, contained in a tank l0. It is then wound on the 7, 1939, Serial No. 277,870

January 31, 1939 pipe I or other piece II to be reinforced. This piece rotates in the direction of the arrow I about its axis l2.

The tank l0 may be provided with heating means for heating the bath 9 and/or with cooling means with air or water circulation or of an other type, the heating and/or cooling means being arranged in any well-known manner not shown, in order to maintain the temperature of the bath at the desired value.

The second terminal of the source 5 is connected through the conductor H to the tank III, so that the wire 2 carries electric current between the brush 3 and the bath 5, provided that this latter is a conductor of electricity.

The operation is as follows: the rheostat l is set in order to provide for the electric heating of the wire 2 to a temperature above one of the points of transformation of the steel or other alloy or metal of which it is composed, for instance to a temperature T which is above 900 C. in the case of steel. On the other hand, the temperature t of the bath 9 is brought to a value below the point of transformation of the metal or alloy of the reinforcing wire, in order that the wire shall maintain a hardened structure (in the case of steel: sorbite, troostite or martensite, etc.).

The reinforcing wire issues from the bath at this temperature near t, and has therefore a certain expansion which is above, equal to, or below the desired amount.

If the expansion is above this amount, there may be provided between the bath and the pipe a sufficient length cf wire or additional cooling means in order that the winding shall take place at the desired lower temperature. On the contrary if the expansion due to the temperature t is unsuflicient, there may be provided additional heating means between the bath and the pipe.

Obviously, the invention is not limited to the embodiment shown and described, which is given solely by way of example.

The tank H) as well as the reel I may be stationary or movable longitudinally along the pipe I l. The device may comprise supplemental rollers or other devices for guiding the wire.

The initial heating may be effected by other means than electrical, for example by one or more gas burners. The lowering of the temperature may be effected otherwise than by means of a bath of melted metal or alloy, for example by means of a jet of cold fluid. In this case, as well as in the case of a bath which is no conductor of electricity, the electric heating circuit the rollers 6, 1

critical point but above room temperature and winding the hardened wire, while still hot and expanded, round the pipe.

2. A unitary process for heat treating steel wire and shrinking same round a pipe comprising the steps of heating the wire to a temperature above the lower critical point of the steel, passing the wire through a liquid bath so as to give the steel a temperature below said critical point but above room temperature and winding the hardened wire, while still hot and expanded, round the pipe.

JACQUES BOUCHER. 

